Thousands of protesters marched to the Saudi embassy on Tuesday, Reuters has reported, protesting against the arrival of Saudi troops to help restore calm in the Sunni-ruled kingdom after weeks of protests by the Shi’ite majority.

Armed vigilantes roamed Manama’s streets and blocked Bahraini villages Tuesday as Iran condemned a military intervention by Gulf troops to help subdue unrest in the Shiite-majority, Sunni-ruled kingdom. According to Zawya, the financial district of Manama was deserted, shops and malls were shuttered and Sunni and Shiite vigilantes armed with metal pipes and clubs were seen in the streets of the capital after hundreds of Saudi-led armoured troops rolled into Bahrain from Saudi Arabia.

Witnesses said vigilante groups also blocked access to a number of villages across the kingdom. Women have been told to leave central Manama and activists were distributing surgical masks and eye protectors to defend against tear gas. There were rumours of a march against the Saudi embassy near the financial district later Tuesday. The troops arrived in Bahrain on Monday to help the Manama government deal with pro-democracy protests which have shaken the strategic Gulf kingdom for the past month. Saudi Arabia’s staunchly Sunni government said it had responded to a call for help from its neighbour under a mutual defence pact of the six-country Gulf Cooperation Council (GCC).

Hundreds of Saudi troops have entered Bahrain to help protect government facilities there amid escalating protests against the government, Al Jazeera has reported. Bahrain television on Monday broadcast images of troops in armoured cars entering the Gulf state via the 26km causeway that connects the kingdom to Saudi Arabia. The arrival of the troops follows a request to members of the Gulf Co-Operation Council (GCC) from Bahrain, whose Sunni rulers have faced weeks of protests and growing pressure from a majority Shia population to institute political reforms.

The Causeway linking Bahrain with Saudi Arabia

The United Arab Emirates has also sent about 500 police to Bahrain, according to Abdullah bin Zayed Al-Nahyan, the Emirati foreign minister. Iran, meanwhile, has warned against “foreign interferences”. “The peaceful demonstrations in Bahrain are among the domestic issues of this country, and creating an atmosphere of fear and using other countries’ military forces to oppress these demands is not the solution,” Hossein Amir Abdollahian, an official from the Iranian foriegn ministry, was reported by Iran’s semi-official Fars news agency as saying.

Debka has reported that the Saudi force that went into Bahrain Monday, March 14, along with UAE and Kuwaiti units, to stabilize the royal regime is larger than reported, consisting of a National Guard brigade, a mechanized brigade of the Saudi army and a tank battalion – altogether 3,500 men. Until recently close American allies, the two Gulf rulers flouted President Obama’s policy of supporting popular uprisings, encouraged by Qaddafi gaining the upper hand against Libya’s rebels and Washington’s constraints against military intervention.

What led the Saudi-led GCC army units to jump unhesitatingly into Bahrain while the US and Europe dithered over Libya? Tehran won’t take this lying down, said Debka Weekly, which (to subscribers only) outlines the potential military showdown between Iran and Saudi Arabia, explores US-Israeli intelligence blindness on Egypt, and reveals how the Libyan conflict is enriching both sides – Muammar Qaddafi and his opponents – as well as global arms traffickers.